The present invention relates to a biosignal measurement device, and is suitable for the technical field of acquiring waves produced and propagated in a living body as electrical signals, or the like.
It is becoming clear that a decrease in the quality or amount (time) of sleep increases the risk of various lifestyle-related diseases, including circulatory diseases such as myocardial infarction and cerebral infarction, or endocrine diseases such as diabetes. Also, extension of or a decrease in the density of REM (Rapid Eye Movement) sleep is being strongly suspected as a cause of depression. Since sleep is thus related to many diseases and social problems modern human beings suffer from, assessing the quality of sleep will continue to grow in importance in the coming years.
Incidentally, polysomnography is known as a method of assessing sleep. Also, there has been proposed an apparatus that measures parameters required for assessing sleep cycle and the quality of sleep from heartbeat, without measuring brain waves (see, for example, PTL 1).